public function build()
{
    $e_nis = $this->ni;
    $e_nama = $this->nam;
    $e_alamat_sekolah = $this->alamat_seko;
    $e_judul = $this->jud;
    $e_pesan = $this->pes;
    return $this
    ->view('permohonan.template_mail', compact("e_pesan"))
    ->subject($e_judul)
    ->attach(storage_path('app/file.pdf'), [
        'as' => 'secret.pdf'
    ]);
}